How to pass variable value from UIPickerView to ViewController?

Question

Swift

Created a UIPickerView in a separate .swift file

import UIKit
@IBDesignable class BorderedView : UIView{
    /// Толщина границы
    @IBInspectable var borderWidth: CGFloat {
        set { layer.borderWidth = newValue }
        get { return layer.borderWidth }
    }
    /// Цвет границы
    @IBInspectable var borderColor: UIColor? {
        didSet { layer.borderColor = borderColor?.cgColor }
    }
    /// Радиус границы
    @IBInspectable var cornerRadius: CGFloat {
        set { layer.cornerRadius = newValue }
        get { return layer.cornerRadius  }
    }
}
class SelectAngleViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
    
    @IBOutlet weak var anglePicker: UIPickerView!
    @IBOutlet weak var saveAngleButton: UIButton!
    
    var array1 = ["90°", "60°", "45°", "30°", "15°"]
    var label = "5"
    
    override func viewDidLoad() {
        super.viewDidLoad()
        anglePicker.delegate = self
        anglePicker.dataSource = self
        view.backgroundColor = UIColor.clear
        view.isOpaque = false
    }
    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String?{
        return array1[row]
    }
    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int{
        return array1.count
    }
    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
            label = array1[row]
    }
    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }
    @IBAction func saveAngleButton(_ sender: UIButton) {
        dismiss(animated: true)
        let actualRow = self.anglePicker.selectedRow(inComponent: 0)
        label = array1[actualRow]
    } 
}

Next, you need to use the selected in the PickerView in the ViewController:

func sRoundTap (dTF: String, qTF: String) -> Double{
        var d: Double = 0
        var angle = ""
        var q : Double = 0
        
        if let dTF = dRoundTapTF.text {
            d = Double(dTF.replacingOccurrences(of: ",", with: ".")) ?? 0
        }
        if let qTF = qRoundTapTF.text {
            q = Double(qTF.replacingOccurrences(of: ",", with: ".")) ?? 0
        }
        let s = CalcAreaFitting.shared.areaTapRound(angle: angle, d: d, q: q)
        return s
    }
    @IBAction func dRoundTapTF(_ sender: UITextField) {
        let s = sRoundTap(dTF: dRoundTapTF.text ?? "0", qTF: qRoundTapTF.text ?? "0")
        sRoundTapLabel.text = "ХХХХХХХХХХ " + "\(s)" + " Х"
    }
    @IBAction func qRoundTapTF(_ sender: UITextField) {
        let s = sRoundTap(dTF: dRoundTapTF.text ?? "0", qTF: qRoundTapTF.text ?? "0")
        sRoundTapLabel.text = "ХХХХХХХХХХ: " + "\(s)" + " Х"
    }

But, unfortunately, the variable is visible only within the function @IBAction func saveAngleButton(_ sender: UIButton)
Please tell me: How can I move the variable outside of this function? How to pass it to ViewController.swift?